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Cutting Welds

03-03-2013, 09:33 PM

I need to cut several stitch welds to remove some casters off the bottom of a cart. I used an angle grinder to cut some of them. I then switched to a mini die grinder to get in some tighter spots; that grinder was very weak. But I still need to remove some more.

The picture shows the tight spot they are in. I cannot get a grinding disc in there and I cannot get a sawzall blade under the caster base.

Can I bust them out with a cold chisel?

I did some reading on arc gouging and plasma cutting but I don't want to buy that kind of equipment just yet.

One post I researched mentioned using a stick welder turned up high and using a conventional rod to melt the weld, and letting gravity do the rest. I have a Thunderbolt AC/DC. Can I do this with the supply of rods I have on hand (I do not know what they are; they came with a welder)? Or do I have to buy some special kind of rod?

Please provide instructions on how I should do this, or point me in the right direction.

If you crank the heat way up you can burn holes with about any rod. That can be effective.

Depending on how well that weld penetrated you could also get a mini-cutoff wheel and put it in a drill and get most of the weld and then chisel the rest. It is basically just a game of what tools you have and what you can readily get. I'm spoiled so I would just grab my plasma and knock it off in a hurry.

BTW, this is a good reason to bolt caster to something. Easy to remove. I like to weld a mount plate and then drill holes to bolt the casters onto the piece.

Comment

It's a bit messy but it can be done with an O/A cutting torch. die grinder will also work. Take a good look at the profiles of carbide cutters available. I have some that are flat on the end with no cutting surface there and flared like an upside-down pine tree. They'd cut it almost loose then as Tackit says get out the chisel and the big hammer.
Meltedmetal

Comment

I have a little HF mini die grinder with a small cut-off wheel that I tried for the first time after my Makita grinder could not get any closer. That thing was nearly worthless; it stalled easily. I'll try switching that wheel to a drill to see if it helps, but it won't help much due to the tight surroundings.

I had thought about cutting off the caster pillers and leaving the plate; that may still be an option. I am going to try and save them becasue these are really nice casters with grease fittings.

I have one of those Port-A-Torch outfits but I have not had the tanks filled yet.

Did some more reading on carbon arc gouging. Says it is hard on 20% duty cycle machines. But then again, I only have a few to remove.

Looks like I will try the hammer and chisel first. I will also go looking for those carbide rotary burrs I have somewhere.

Comment

carbon arc gouging is good, if you have never done it before, use a different method, once you make contact, its go, you can destroy stuff in seconds, of if not experienced, a weld can become glazed over and then the arc wont touch it, carbon bit in die grinder is the answer, buy the good bits, they are about 20 bucks, the 4 dollar bits will not work

If you have an oxy/acet torch setup I would just use a scarfing tip on the torch to remove it.

It looks like you now have a good reason to get those tanks filled. This method will probably be the easiest way out of this situation^^^^. And you can pick up the scarfing tip while getting the tanks filled. What good is having the torch out fit and empty tanks anyway?

Comment

Plasma arc gouging works extrmely well for blowing out welds. It is easy to control the depth and width, very easy and fast. Many newer technology air plasma torchs have special gouging nozzle that create a softer arc....made specifically for gouging.
Jim Colt

I need to cut several stitch welds to remove some casters off the bottom of a cart. I used an angle grinder to cut some of them. I then switched to a mini die grinder to get in some tighter spots; that grinder was very weak. But I still need to remove some more.

The picture shows the tight spot they are in. I cannot get a grinding disc in there and I cannot get a sawzall blade under the caster base.

Can I bust them out with a cold chisel?

I did some reading on arc gouging and plasma cutting but I don't want to buy that kind of equipment just yet.

One post I researched mentioned using a stick welder turned up high and using a conventional rod to melt the weld, and letting gravity do the rest. I have a Thunderbolt AC/DC. Can I do this with the supply of rods I have on hand (I do not know what they are; they came with a welder)? Or do I have to buy some special kind of rod?

Please provide instructions on how I should do this, or point me in the right direction.

Comment

Well, I found some burrs but they turned out to be made from high speed steel; did not work too well.

Beat the daylights out of a weld with a cold chisel. Very, very slow progress.

Today I called my LWS to see about filling my little tanks. I also ordered a scarfing tip. They had to special order it for the size 3 torch. They gave me a nice break on the retail price too. Plan to pick it up on Saturday.

I will have to keep looking for the 1 inch wheels. The smallest that the LWS carried were 3 inch.

Comment

Use an abrasive wheel on a 4 1/2" angle grinder, cut straight down. It will cut the leg on the side as well, then just weld up the part that was cut on the side if you are trying to save it. Once one side of the caster is cut you should be able to pry up on it and likely break the weld on the other side fairly easily. As an alternative you could use a grinding stone perpendicular to teh weld and gouge down on the caster. This will leave a bevel where the weld was, but will not cut through the side of whatever it is on. You can weld up the bevel when you weld it on the next project